1. Field of the Invention
The present invention relates to an improved golf club head and, more specifically, a club head of the "iron" type, having an improved mass distribution. Further, the invention is directed to a golf club having such a head.
2. Description of Background and Relevant Information
Most modern golf club heads of the "iron" type have a rear cavity thereby creating a substantial peripheral mass distribution. Clubs of this type have won the confidence of golfers and have gradually replaced the old blade-shaped irons, which are much less forgiving and which are therefore mostly used by more experienced players.
Examples of "cavity back" irons having such a mass distribution are described in U.S. Pat. Nos. 5,014,993; 5,242,167; and 5,393,113.
A new level in club head design has been achieved recently by combining a peripheral mass distribution with an oversized head. This leads both to maximizing the inertia and increasing the size of the "sweet spot". By increasing the inertia, the rotation strength of the head is increased during off-center shots and a satisfactory ball trajectory is thereby maintained.
Nevertheless, numerous tests have made it possible to determine that it is important to adjust precisely the position of the center of gravity in order to control perfectly the trajectory of the ball and to avoid lateral deviations of the ball. In particular, it has been found that most irons provided with a peripheral mass distribution combined with an enlarged impact surface have a trajectory with a clear tendency to deviate from left to right (i.e., a slice) for a right-handed golfer.
That tendency has made it possible to show that lowering the center of gravity with respect to the impact face provides the golfer with a better "touch" on the ball and it increases the back-spin necessary for the ball to be able to fly properly along a desired trajectory and for the player to work the ball sufficiently and give it the desired effect, such as a more or less pronounced tendency for the ball to "back-up" once it lands on the green, for example.
Likewise, it has proven important that the position of the center of gravity comes closer to the heel to correct the ball's natural tendency to move towards the right and which becomes accentuated particularly as the golfer selects a club from among the long irons (from a No. 1 to a No. 3 iron, in particular). It has been noted in fact that the position of the center of gravity of a club head is closely correlated with the direction of the trajectory taken by the ball. In short, one can say that the ball goes where the center of gravity is positioned.
For the heads of most irons whose impact surfaces are enlarged or oversized, it has been found necessary to correct the position of the center of gravity in order to adjust perfectly the trajectory of the ball. This correction is not to be made to the detriment of either the important inertia values obtained, or to the general shape of the head, in order not to disturb the player's confidence in his/her golf game. In particular, the head should have a normal appearance when the club is positioned at address, with an upper edge portion of the club head having a standard appearance and size so as not to disturb the golfer.